Apparatus for heating stills



Mara, 15, 1927.

' G. D. WHITE APPARATUS FORHEATING STILLS 4 She ets-Sheet 1 Filed April 5, 1925 Swa m AMSLL March 15, 1927. 1,621,298

G. D. WHITE APPARATUS FOR HEATING STILLS Filed April 5, 1923 4 Sheets sheet 2 l 1 I l l J March 15, 1927. G. D. WHTE 1,621,298

APPARATUS FOR HEATING STILLS Filed April 5, 1923 4 ts-Sheet s bwm III IZZY. I: 1': I l 1 1 1 2 March 9 7 G. D. WHITE APPARATUS FOR HEATING STILLS 4 Sheets-Shee t 4 Filed April 5, 1923 Patented Mar. 15, 1927.

UNITED STATES PATENT OFFICE.

GEORGE D. WHITE,

APPARATUS FOR HEATING s'rILL's.

Application filed A ril 5,

This invention relates generally to improvements in heating apparatus for stills in which hydrocarbon oils are distilled and has particular reference to the provision of suitable heating means for stills in which is carried on the decomposition or'cracking of oil.

In the cracking of hydrocarbon oils difficulty has been experienced in applying to the stills the heat required to carry on the cracking operation because the'.decomposition is attended with a formation of-com- ,paratively large quantities of carbon or coke which readily becomes attached to heated metal walls, and since with the heating apparatus which has been commonly employed for heating stills it has been necessary to carry furnace temperatures considerably in excess of the temperature desired in the stills in order to maintain such temperture there in. The application of this heat to the carbon coated metallic surfaces produces red spots with the resultant deterioration and distortion of the metal and the breaking down of the stills. When the stills are operating under high pressure not only is the length of a run out down in this manner but the operation is attended with great hazard. Moreover in the various types of liquid fuel burning furnaces which have hitherto been used a considerable draft is ordinarily required in the furnace to maintain the stills at the cracking temperature and it has been impossible to avoid localized overheating of those portions of the stills in the more direct path of the draft. Moreover the great draft used necessitates the use of an excessive amount of fuel.

Some of the objects of my invention are, therefore, to provide means for reducing the temperature differential between the furnace and the still, to reduce the amount of draft required and to provide heating means by which an even heat is applied to the still and in which localized overheating is-largely avoided.

Another object is to provide means for accurately regulating and. controlling the temperature in various parts of the furnace so as to obtain thereby a more accurate controlof the cracking operation in the stills.

. In the ordinary type of oil or coal fired furnaces, which are commonly used for cracking stills, it is not possible to'obtain that 1923. Serial No. 630,001.

regulation of the temperature in the furnace which is necessary to carry on the cracking operation to the best advantage.

A further object is toprovide means for rapidly cooling the stills at the completion line 2-2 of Figure 1.

Figure 3 is an end elevation.

OF PORT ARTHUR, TEX AS, ASSIGNOR TO THE TEXAS COMPANY, OF NEW YORK, N. Y., A CORPORATION OF TEXAS.

Figure 4 is a sectional plan view taken on the line 44 bf Figure 1.

Figure 5 is a multi-sectional plan view taken on the lines 55 of Figure 1.

Figure 6 is a detailed sectional view illustra'tlng a preferred manner of mounting the burners in the furnace.

The invention has reference to apparatus for heating stills, converters and the like, either of the horizontal or vertical type. As the invention, however, provides especiall advantageous heating equipment for vertical stills, it is illustrated and described in detail herein as thus applied. In the particular example of the invention illustrated it is shown as employed with a plurality or battery of stills or converters; it is to be understood, however, that theinvention contemplates heating a paratus for stills arranged singly or in mu tiple. In the embodiment of the invention thus illustrated then the invention is shown as applied to a plurality of vertical stills 10. Each still-is adapted to be heated in its intermediate arranged with a comparative cool portion at the bottom for the purposes of carbon and residuum collection and removal and with a vapor space above the furnace. As

which, as shown, is arranged about the stills.

in substantially oval or elliptical form. While the furnace may be constructed in the portion, and is- I is em loyed and an ellipse when a plurality of sti ls are used.

Exteriorly of the fire brick wall 13 is a wall 14 composed of diatomaceous earth, asbestos, or magnesium slabs or other suitable insulating material. 'Bulk asbestos may be used, if desired, being packed in between l walls of the furnace; for obvious advantages in construction, however, it is preferable to use slabs. The furnace includes an exterior wallpreferably in the form of a metallic casing, such as a steel casing 15. By con structing the furnace with an outer steel wall,- an inner refractory wall and an intermediate insulating wall it is possible to substantially revent loss of heat by radiation while at the same time avoiding the thick and heavy furnace constructions commonly employed.

The furnace is shown as being supported on pillars or concrete blocks 16 so that the stills may be supported above the ground surface in order that access may be had to the bottom of the stills for cleaning puroses' and the like. As shown in the drawmg the bottom of the furnace may comprise a fire brick floor 17,. an exterior concrete floor 18 and an intermediate layer of sand 19. The furnace is provided with a closure at the top which referably assumes the form of a suspen ed tile arch 20. The means for su porting the still in the furnace is ositioned outside of the furnace. Thus each still may be equipped with a plurality of lugs 21 which are adapted to rest on I beams 22 arranged above the tile arch 20. I

The furnace is provided with a plurality of openings or conduits '23 which extend through the wall of the furnace. The outer end of each conduit is inclined as shown in the drawings and a hinged door 24 is adapt-' ed to form a closure over the outlet. The weight of the door is sufficient to normally retain the gases within the furnace-but in case ofan explosion the door will swing on its hinge so as toopen and relieve the pressure inthe furnace. Two rows of conduits 23 are preferably provided one row being near the top of the furnace and the other row near the bottom. At the conclusion of a run the doors 24 may be opened and the ensuing circulation through the furnace and about the stills 10 effects a rapid cooling of the furnace and stills. It will be observed that the stills are spaced from the furnace walls so that the air entering the conduits 23 may readily come in contact with the ex terior still surfaces. In practice this artrolled independently of the others.

rangcment greatly reduces the time required for cooling the stills at the end of arun.

, Gas or fuel for the furnace is supplied from a suitable source by means of the pipe 25 which, as illustrated, terminates in branch and each connecting line 28 has a valve 31 so that each burner may be regulated and con- As clearly shown in Figure 6, each burner extends through a hole 32 in the furnace Wall. Into each opening 32 is closely fitted a pipe or sleeve 33 and asbestos or other suitable packing or insulating material 34 is insertedwithin the sleeve so as to form a tight joint about the burner 29. Adjacent each burner is a small opening through the furnace wall into which is inserted a pipe 35 provided with a removable cap orclosure 36. The pipe 35 serves as a means for introducing a torch inside the furnace for the purpose of lighting the gas burner 29.

The vertical pipes 27 are positioned at points preferably between the several stills and the burners are arranged at such angles as to direct the flames into the spaces intermediate the stills. In this way the flames 'do not impinge directly on the surfaces of the stills. The result is that localized overheating is avoided and a substantially even heat is applied to the still surfaces.

By means of the several valves inthe gas lines the quantity and degree of heat from plied to each individual still may be so regu lated as to maintain the same or difierent temperatures in different portions of the still under the varying conditions of opera: tion which may be encountered. Thus, for

example, it may be desired to introduce the oil being treated, or to return reflux condensate, to a given portion of the still, in which cases a higher temperature may be applied with safety to that portaion of the still receiving the fresh oil an" in fact, it is ordinarily desirable to apply a higher temperature or a greater amount of heat to that portion of the still which receives the charge or the reflux, and in case of a battery of stills to apply moreheat to the still rerfiiiving the fresh oil than to the other sti s.

It h been found that in the liquid phase and that, for example, asuccessful commer-- cial operation may be carried on in which higher boiling oils are converted into lower boiling products by being maintained at a temperature, at which an eflicient rate of decomposition. occurs,'for' a time sufiicient to cause a substantial conversion, in this way avoiding the relatively high vapor phase cracking temperatures which have sometimes been employed.' The oil to be thus treated may be passed successively through a plurality of stills, as 10, arranged to be heated in the manner described herein. The oil attains successively advanced stages of decomposition in its passage from one still to another and the furnace temperatures about each still respectively, may readily be controlled to meet this condition and maintain the desired cracking temperature in the stills.

It is apparent that the furnace temperatures required about the several stills or reaction chambers will vary with conditions of operation, such as, what particular stills,

- a lower temperature, whether the charge is introduced into one still and is passed to the others in succession or whether the charge is split among a plurality of the stills, and other variable factors as will be understood by those skilled in the art. Whatever the conditions of operation may be, however, by means of my invention the several converters may be maintained at the desired temperatures.

If desired the furnace may be equipped with a ring burner 37 positioned near the bottom of the furnace. I have found, however, that ordinarily the ring burner is unnecessary and that it is generally more advantageous to use merely the horizontal burners disposed at various elevations as has been described herein. 4

The furnace gases are drawn off from the furnace chamber through a plurality of openings 38 positioned near the top of the furnace. These openings lead to a gas conduit 39 arranged about the furnace and ter minating in an outlet pipe or flue 40 which is provided with a damper 44. When operating conditions have been established the damper may be choked in order to hold the hot gases in the furnace chamber. In this manner the desired temperatures in the stills can be maintained with a minimum of fuel, since an excessive draft through the furnace chamber is avoided and the gases are retained in the furnace for a time sufiicient to insure a maximum transfer of heat to the stills. If desired the gases may be remo ed fromthe fiirnace chamber through pneor morelepenings at either one of the sides or ends of the furnace. It is generallypreferable, however, to provide a plurallty of openings extending about the entire furnace, such as is illustrated in the drawings.

The furnace maybe equiped with a numher of peep holes 41 and with such thermometers, pyrometers and the like as may be deemed necessary or desirable. As clearly shown in Figure 3 Stairways-42' and-platforms 43 are provided in order that the attendants may have ready access to the doors 24, the burners, peep holes and the like.

The use of the apparatus of my invention effects a substantial reduction of the temperature differential between still and furnace which is highly desirable, since the lower the temperature applied to the exterior still surface the less the tendency to bake carbon deposits on the interior still walls. I11 order to indicate the superior advantage gained in employing my heating apparatus it may be stated that in some cases the invention has been applied in carrying on the cracking of petroleum hydrocarbons in a series of stills maintained at temperatures around 700 F. to 800 F. To hold this temperature in the stills, under the different operating conditions employed. furnace temperatures from around 800 F. to 1200 F.

were used. When using the old types of heating equipment furnace temperatures of 1600 F. and even higher had been necessary to maintain the cracking temperatures indicated under the same operating conditions.

Apparatus of preferred form and constructlon has been illustrated and described for the purpose of showing a way in which this invention may be used but the inventive thought upon which the application is based tributed points withinthe furnace in such a manner as to avoid direct contact of the flames against the still walls whereby hot spots are prevented, and a plurality of flue passages spaced from each other in the upperpart of the furnace whereby the furnace gases are caused to travel upwardly through the furnace and are withdrawn at distributed points in the upper part thereof.

2. In furnace apparatus for crackingstills, bustion gases and a plurality of openings in the combination with a battery of Vertical the furnace wall establishing communication stills, of a furnace chamber within which between the furnace chamber and the out- 10 the stills are mounted, a plurality of gas side atmosphere and doors for said openings.

- fiburners distributed throughout said cham In witness whereof I have hereunto set her, a plurality of outlets in the upper part my hand this 21st day of March, 1923. of said chamber adapted for removing com- GEORGE .D. WHITE. 

